PROJECT SUMMARY/ABSTRACT Significant disparities in early reading proficiency prevail in the United States, as more than half of all school- aged children are reading below standard grade levels. Dyslexia, a prevalent learning disorder specific to reading, is currently only reliably identified after demonstrated failure with learning to read, which can negatively impact socio-emotional well being and academic achievement. Early identification of children at risk for dyslexia offers the potential to lessen the negative consequences of difficulty learning to read, however, current methods utilized are not sufficient to effectively identify children at risk early on. Therefore, evaluating the mechanisms that underlie literacy development offers the potential to optimize approaches to early identification. As learning to read is a complex, multi-faceted process that relies on several speech and language-related sub-skills, one approach is to investigate how these sub-skills contribute to literacy development. To date, one sub-skill that remains understudied is the role of speech production accuracy in contributing to subsequent literacy skills, despite evidence that some children with disordered speech production, known as speech delay, develop reading difficulties. Furthermore, it remains unknown whether speech delay and reading difficulties stem from shared or distinct underlying bases. Therefore, studying brain morphology at an early age may uncover the underlying mechanisms associated with speech delay versus early risk for dyslexia, and discern the neural mechanisms that lead to reading difficulties. To further investigate the mechanisms that underlie subsequent reading difficulties, the proposed research will take a multidimensional approach to investigate the behavioral and neural links between speech accuracy, pre- literacy skills, and subsequent literacy skills. The proposed research will build upon an ongoing longitudinal investigation of 186 children with/without behavioral risk for dyslexia (as indicated by pre-literacy skills) from kindergarten through second grade (NIH?NICHD R01 HD067312), and retrospectively identify children with/without speech delay through percent consonant correct (PCC) analysis of speech recordings. The proposed research will be the first to investigate brain morphology in kindergarteners with/without speech delay relative to those with/without risk for dyslexia, which will delineate the structural correlates of speech delay while accounting for early risk for dyslexia. The longitudinal aspect of this research will further investigate the relationship between early speech accuracy, early behavioral risk for dyslexia, and subsequent literacy skills through mediation and moderation analyses. In addition, the proposed research will examine to what extent behavioral and neural indicators of early speech accuracy and pre-literacy skills may explain subsequent literacy skills. Overall, the proposed research seeks to uncover the underlying mechanisms that give rise to literacy skills, and optimize prediction of subsequent literacy skills early on. This research may offer significant implications for jointly evaluating speech production accuracy and risk factors of dyslexia in early identification.